Sheet processing apparatus

ABSTRACT

A sheet processing apparatus takes out postal matters that are inserted by a take-out roller, and separates them in sheets by a feed roller and a reversing roller, and feeds into the apparatus. A cleaning roller having rubber sponges having foamed vesicles in mean diameter 50 to 500 μm is provided to the feed roller in contact with it. Paper-dusts on the surfaces of the feed roller and the reversing roller are removed by driving this cleaning roller to rotate at a velocity equal to or higher than a rotating speed of the feed roller.

CROSS REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2004-147807 filed on May 18,2004; the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a sheet processing apparatus that is providedwith a cleaning roller to remove paper-dust adhered to members tocontact sheets in a sheet processing apparatus such as, for example, apostal matter processing apparatus, a banknote processing apparatus andthe like.

DESCRIPTION OF THE BACKGROUND

In recent years, a sheet processing apparatus such as a postal matterprocessing apparatus, a banknote processing apparatus, etc. is providedwith devices to take out sheets one by one from a bundled state in atake-out portion as disclosed in the Japanese Patent ApplicationPublication No. 2003-81461. Such take-out devices are broadly dividedinto a friction type using a rubber roller and a suction type using asuction drum. In a friction type take-out device using a rubber roller,more than two sheets may be taken out and are supplied into a sheetprocessing apparatus after separated into a single sheet.

In such the sheet take-out device, the frictional force of the rubberroller surface largely affects the sheet processing capacity and it istherefore important to keep a frictional coefficient of the rubberroller surface always stable.

However, in a postal matter processing apparatus or a banknoteprocessing apparatus for processing sheets at a high-speed, fabrics onsheet surfaces come apart violently and paper-dust is generated in largeamounts. Paper-dust generated tends to adhere to paper feeding rubberrollers of high frictional coefficient. When paper-dust is adhered tothe rubber roller surface, its frictional coefficient drops sharply. Asa result, such a trouble is generated as it becomes difficult to takeout sheets one by one as explained above.

SUMMARY OF THE INVENTION

An object of this invention is to provide a sheet processing apparatusthat is capable of efficiently cleaning paper-dust adhered to such sheetconveying means as a take-out roller, a feed roller, a conveying roller,a conveying belt, etc.

According to the embodiment of this invention, there is provided a sheetprocessing apparatus comprising conveying means for conveying sheets incontact with them; processing means for performing a specified processof the sheets conveyed by the conveying means; and a cleaning roller ofwhich surface is formed of a porous material to remove paper-dust fromthe surface of the conveying means by rotating in contact with theconveying means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of the rough construction of a postal matterprocessing apparatus showing a face culler canceller (a post-officestamp)that is a part of the postal matter processing apparatus in anembodiment of this invention;

FIG. 2 is a rough construction diagram showing the vicinity of atake-out portion of the face culler canceller (the post-office stamp)shown in FIG. 1;

FIG. 3 is a top view showing the state where one sheet of postal matterfed between a feed roller and a reversing roller;

FIG. 4 is a top view showing the state where two sheets of postal matterare fed between the feed roller and the reversing roller;

FIG. 5 is a conceptual diagram of the experiments conducted for thepaper-dust collecting capacity of a sheet of paper and a roller shapedmember;

FIG. 6 is a graph showing the results of the experiments conducted forthe materials or roller and paper-dust gatherring capacity;

FIG. 7 is a graph showing the relationship between diameter of vesicleof sponge and weight of paper-dust gatherring amount;

FIG. 8 is a conceptual diagram showing a usage pattern of a feed roller,a reversing roller and a cleaning roller; and

FIG. 9 is a graph showing the results of the experiments conducted forthe relative rotational speed of the feed roller and the reversingroller (a peripheral speed difference of rollers) and a gathering rateof paper-dust.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiment of this invention applied to a postal-matter processingapparatus will be explained below referring to the attached drawings asan example of a sheet processing apparatus to realize this invention.

FIG. 1 is a top view showing the rough construction of a face cullercanceller 1 of a sheet processing apparatus involved in the embodimentof this invention, which cancels postal indicias such as stamps pastedon postal matters P, sorts and stacks them.

Face culler canceller 1 is composed of an insert port 2, a take-outportion 4, an inspection portion 5, a rejection stacker 6, detectors 7 aand 7 b, a reversing portion 8, a sealing portion 9, and a sortingstacker 10. Postal matters P (sheets) that are subjects for processingare inserted into insert portion 2 in the arranged state in the uprightposition. In take-out portion 4, plural postal matters P inserted in thestated of the upright position through insert portion 2 are taken out ona conveying route 3 in order from postal matters at the end in the stackposition one by one. Inspection portion 5 inspects postal matters Ptaken out on conveying route 3 for postal matters containing foreignmatters and irregular-size postal matters. Postal matters that arejudged to contain foreign matters/in irregular-size by inspectionportion 5 are stacked in reject stacker 6. Inspection portions 7 a and 7b detect postal indicias pasted on the surfaces of postal matters Ppassed through inspection portion 5 and judged to be normal postalmatters that can be processed. In reversing portion 8, postal matters Pare turned over upside down selectively based on the detection result ininspection portions 7 a and 7 b. In sealing portion 9, postal indiciaspasted on postal matters P passed through reversing portion 8 arestamped as necessary. Sorting stacker 10 is composed of sorting boxes 10a to 10 f and postal matters P are sorted and stacked in sorting boxes10 a to 10 f according to the detection results by detectors 7 a and 7b. Detectors 7 a and 7 b, reversing portion 8 and sealing portion 9partially comprise the processing means to make the face cullercancellation.

Face culler canceller 1 displays various operational guides to operatorand an operation panel 11 to accept various operating inputs made byoperator is provided near insert portion 2.

In insert portion 2, plural postal matters P are housed in the state ofupright position with the long side in contact with the base. Postalmatters P inserted through insert portion 2 are inserted in the looseupside-down and front/back state. Insert portion 2 has a backup plate 2a to press all housed postal matters P toward take-out portion 4 alongtheir stacking direction.

Take-out portion 4 takes out postal matters inserted into insert portion2 from the most remote end at the opposite side of pickup plate 2 a onconveying route 3 one by one. On conveying route 3 extending fromtake-out portion 4 to sorting stacker 10, there are a branch gate 12 forbranching conveying route 3 to reject stacker 6, a branch gate 13 forsorting postal matters P passing through reversing portion 8 in twodirections, and sorting gates 14 a to 14 e for branching conveying route3 to six sorting boxes 10 a to 10 f of sorting stacker 10.

The details of the vicinity of take-out portion 4 of face cullercanceller 1 will be explained referring to FIG. 2.

In FIG. 2, supplied postal matters P are pressed to a take-out roller 20side by backup plate 2 a (not shown in FIG. 2) and a postal matter P atthe most remote side is supplied to a feed roller 21 side by take-outroller 20. A reversing roller (a separation roller) 22 that will bedescribed later is provided facing to feed roller 21. Conveying rollerpairs 23 and 24 are provided at the inner side from feed roller 21 inthe apparatus to convey postal matters P to inspection portion 5.

A cleaning roller 27 that is described later is provided to rotate incontact with take-out roller 20, feed roller 21 and conveying rollers23, 24.

How to separate postal matters P will be explained referring to FIG. 3and FIG. 4. In take-out portion 4, postal matters P are supplied toroller 21 side by take-out roller 20 that is positioned at one end ofstacked postal matter bundle P. When only one postal matter P issupplied as shown in FIG. 3, reversing roller 22 is turned jointly withpostal matter P1 and rotated (normal rotation) in the same direction asthe feeding direction of postal matter P1. FIG. 4 is a diagram showing acase wherein two postal matters are taken out by take-out roller 20. Inthis case, reversing roller 22 rotates in the reverse direction andpushes back a second postal matter P2. After a sensor (not illustrated)detects that a first postal matter P1 passed completely, second postalmatter P2 is sent to feed roller 21. When this postal matter P2 is onesheet, reversing roller 22 is rotated again in the normal direction.Thus, only one postal matter is always taken out. The normal/reverserotation of reversing roller 22 is switched by a torque limiter 25. Thatis, torque limiter 25 is provided to the shaft portion of reversingroller 22. When postal matter P1 is only one sheet, a prescribed forceis transmitted to reversing roller 22 from feed roller 21 through postalmatter P1 and torque limiter 25 is idling and reversing roller 22 isrotated jointly in the normal direction. On the other hand, when twosheets of postal matter P are taken out, a conveying force of relativelysmall frictional coefficient between paper sheets only is transmitted tothe second postal matter P2 and therefore, torque limiter 25 ofreversing roller 22 acts to reverse rotate reversing roller 22. Further,when there is no postal matter and feed roller 21 contacts reversingroller directly, the frictional coefficient between rollers is high andtorque limiter 25 idles and reverse roller 22 is rotated jointly withfeed roller 21.

Next, selection of materials for cleaning paper-dust is explained. FIG.5 is a conceptual diagram showing the experiment made for a paper-dustgatherring capacity of a sheet of paper 50 using a roller-shape member.After sliding a roller 51 rotating at a constant speed with a constantload applied on sheet of paper 50 moving at a constant speed, weights ofpaper-dust on the surface of roller 51 were measured. Paper-dust weightswere measured on roller 51 using various rubber sponges, rubbers, nylonsponges, nylon brushes, leathers and nonwoven clothes, respectively.Materials in hardness within the ranges of HA20 to HA90 (JIS K 6253 TypeA) were evaluated. As seen from FIG. 6 showing the results ofexperiments, paper-dust collection capacity is excellent in rubbersponge, nonwoven cotton cloth and nonwoven rayon cloth and it wasrevealed that soft materials have especially high paper-dust collectingcapacity.

The relationship of vesicle diameter of sponge with gathered paper-dustweights was examined. As seen from FIG. 7 showing the examined results,it was revealed that gathered paper-dust weights were much in a range ofdiameter of vesicle 50 to 500 μm of sponge and extremely less atdiameter of vesicle 10 μm and 1000 μm. When the paper-dust adhered statewas observed through an optical microscope, it is confirmed thatpaper-dust is captured and adhered in sponge vesicles. Cellulose fibersthat are principal component of paper-dust are 10 to 50 μm in diameterand 0.5 to 4 mm in length. Therefore, this is considered because thecatch-up rate of paper-dust becomes low when sponge vesicles are smallerthan 50 μm, and the sponge surface becomes rough when sponge vesiclesare larger than 500 μm.

As a result of the experiments described above, it was found that rubbersponge in hardness HA50 (JIS K 6253 Type A) and mean vesicle diameter 50to 500 μm is adequate as a material for a cleaning roller.

Next, a using pattern of cleaning roller 27 will be described. FIG. 8 isa conceptual diagram showing the using pattern of feed roller 21,reversing roller 22 and cleaning roller 27 described above. In FIG. 8,feed roller 21 and reversing roller 22 are kept in contact with eachother except a time when a postal matter P passes. Paper-dust fallingfrom postal matter P is adhered to the surfaces of both rollers of feedroller 21 and reversing roller 22. FIG. 9 shows the results ofexperiment to examine to which roller of feed roller 21 and reversingroller 22 in contact with each other paper-dust adhered on theirsurfaces moved when a relative rotational speeds of both rollers (adifference in roller peripheral speeds) were optionally changed. It wascleared that when a relative speed difference becomes large, paper-dustwas concentrated on the roller at a high-speed rotating side but weightsof paper-dust adhered on both rollers tend to be divided equally.

That is, in the case of reversing roller 22 shown in FIG. 8, paper-dustis adhered much to reversing roller 22 side that is mainly slidingtogether with postal matter P immediately after postal matter P passed.However, when two rollers of both feed roller 21 and reversing roller 22are joint turned at a high-speed after postal matter passed, paper-dustis divided on both rollers almost equally 2, 3 seconds later. Cleaningroller 27 is in contact with feed roller 21 and driven to turn at ahigher speed than feed roller 21. Accordingly, paper-dust adhered tofeed roller 1 is collected to cleaning roller 27 and paper-dust attachedto reversing roller 22 is also collected to cleaning roller 27 throughfeed roller 21 and cleaned simultaneously.

In a case wherein a large volume of paper-dust is generated in a shorttime as in a postal matter processing apparatus, cleaning roller 27 iscovered by paper-dust in several hours. Cellulose fibers are capturedmechanically in sponge vesicles of cleaning roller 27 and therefore,paper-dust will not drop from cleaning roller 27 when two rollers arerotating jointly. Feed roller 21 and reversing roller 22 are cleanedwith the driving of the apparatus and a paper-dust layer is formed onthe surface of cleaning roller 27. This paper-dust layer becomes anonwoven cotton (cellulose fiber) cloth roller in a manner. Because ofthis, as can be presumed from a graph shown in FIG. 6, a nonwoven cottoncloth is high in paper-dust gatherring performance and even when apaper-dust layer is formed on the surface of cleaning roller 27, itspaper-dust gatherring performance does not drop. Further, the increaseddiameter of cleaning roller 27 by paper-dust is absorbed by the elasticdeformation of sponge.

The diameter of cleaning roller 27 is increased gradually by apaper-dust layer. In order to limit the amount of this increase in thediameter, a scraping plate 28 is provided at a position separated by afixed space from cleaning roller 27 as shown in FIG. 8. As a result ofthis scraping plate attached, paper-dust adhered to cleaning roller 27is scraped off by scraping plate 28 when cleaning roller 27 is rotated.Further, the paper-dust layer can be. peeled off easily with a toothbrush or other cleaning jigs, and a frictional coefficients of feedroller 21 and reversing roller 22 can be maintained for an extendedperiod without dropping the take-out efficiency when cleaning roller 27is cleaned in a periodic maintenance work.

Further, in the above embodiment, feed roller 21 and reversing roller 22are explained. Cleaning roller 27 may be provided so as to rotate incontact with take-out roller 20, conveying roller 23 and further,conveying belt 24 as shown in FIG. 2. It is clear when providingconveying roller 23 and conveying belt 24, it is effective to install acleaning roller to both of two conveying rollers and the conveying beltwhich are rotating in contact with each other.

In the above embodiment, the apparatus is explained by taking an exampleof the take-out roller as a friction roller. It is also possible to makethe take-out roller as a suction take-out device using a suction drumfor a take-out unit. In this case, a cleaning roller is provided only tosuch a conveying means as conveying roller, conveying belts, etc. When acleaning roller is provided in contact with a conveying roller/aconveying belt, etc., a cleaning roller should be driven to rotate witha relative velocity difference between peripheral velocities ofconveying roller and conveying belt as described above.

Further, in the embodiment described above, the apparatus is explainedby taking postal matters as an example but it can be also applicable tosuch processing apparatus as a banknote processing apparatus, a copier,a printer, etc.

This invention is not restricted to the embodiment described above but,needless to say, it can be modified variously without departing from thescope thereof.

According to this invention, it is possible to provide a sheetprocessing apparatus that is capable of efficiently cleaning paper-dustattached to conveying means such as a take-out roller, a feed roller ora conveying roller, a conveying belt, etc.

1. A sheet processing apparatus comprising: conveying means forconveying sheets in contact with them; processing means for performing aspecified process of the sheets conveyed by the conveying means; and acleaning roller of which surface is formed of a porous material toremove paper-dust from the surface of the conveying means by rotating incontact with the conveying means.
 2. The sheet processing apparatusclaimed in claim 1, wherein the conveying means includes a take-outroller to take out sheets by contacting a sheet at the most far end ofplural sheets supplied, and the cleaning roller removes paper-dust fromthe take-out roller by contacting it.
 3. The sheet processing apparatusclaimed in claim 2, wherein the conveying means includes a feed rollerto feed sheets taken out by the take-out roller into the apparatus, andthe cleaning roller removes paper-dust from the surface of the feedroller by rotating in contact with the feed roller.
 4. The sheetprocessing apparatus claimed in claim 3, wherein the conveying meansincludes a separation roller that is press contacted to the feed rollerand is given with a rotational torque in the direction reverse to thesheet feeding direction to separate the sheets sent out by the feedroller one by one, and the cleaning roller removes paper-dust adhered onthe surface of the separation roller through the feed roller.
 5. Thesheet processing apparatus claimed in claim 1, wherein the conveyingmeans includes a conveying roller and the cleaning roller removespaper-dust from the surface of the conveying roller by rotating whilecontacting the conveying roller.
 6. The sheet processing apparatusclaimed in claim 1, wherein the conveying means includes a conveyingbelt and the cleaning roller removes paper-dust from the surface of theconveying belt by rotating while contacting the conveying belt.
 7. Thesheet processing apparatus claimed in claim 1, wherein the porousmaterial is a rubber sponge.
 8. The sheet processing apparatus claimedin claim 7, wherein a mean diameter of vesicles of the foamed rubbersponge is 50 to 500 μm.
 9. The sheet processing apparatus claimed inclaim 7, wherein the rubber sponge is formed in a continuously foamedmaterial.
 10. The sheet processing apparatus claimed in claim 1, whereinthe cleaning roller is rotated jointly with the contacting conveyingmeans at a velocity equal to or higher than a conveying velocity of theconveying means.
 11. The sheet processing apparatus claimed in claim 1further comprising: a scraping plate provided by separating for aspecified distance from the cleaning roller for limiting volume ofpaper-dust attached to the cleaning roller to a specified volume.